/Engine/Source/Runtime/RenderCore/Public/VirtualTexturing.h
Makes a request for the given page data. For data sources that can generate data immediately, it's reasonable for this method to do nothing, and simply return 'Available' Only called from render threadFVTRequestPageResultdescribing the availability of the request
[FVTRequestPageResult](API\Runtime\RenderCore\FVTRequestPageResult) RequestPageData ( [FRHICommandList](API\Runtime\RHI\FRHICommandList) & RHICmdList, const [FVirtualTextureProducerHandle](API\Runtime\RenderCore\FVirtualTextureProducerHandle) & ProducerHandle, uint8 LayerMask, uint8 vLevel, uint64 vAddress, EVTRequestPagePriority Priority )